"We expect a release candidate of Rails 3.0 ready by RailsConf," said Rails founder David Heinemeier Hansson in an email on Tuesday. RailsConf, a technical conference for Rails developers, will be held in Baltimore the week of June 7.

The incorporation of Merb features into Rails 3.0 is intended to provide performance and speed improvements. Version 3.0 has been slated to feature a new router focused on RESTful declarations. Other improvements planned have included an Action Rails 3.0 API and an Active Record chainable query language based on relational algebra. JavaScript helpers have been planned as well.

Meanwhile, builders of Rails earlier this week have been announcing incremental upgrades to Rails. The latest of these was Rails 2.3.8, to fix issues with version 2.3.6. The 2.3.6 release features cross-site scripting prevention to match Rails 3.0 as well as Active Record improvements. The 2.3.8 release followed the 2.3.7 update, which a Rails blog says "slipped out the door too hastily." The blog cites issues with the rails_xss plugin addressing cross-site scripting.

"Fixing compatibility with the rails_xss plugin inadvertently forced everyone to use it," the blog says.